The present invention relates to a fastening tool for a screw element having a tool mount and an associated line, as well as to a coupling part for the fastening tool and to a screw element configured for a cooperation with the coupling part and/or the fastening tool.
Screw elements which serve for the attachment of a line to a counterpiece, be it to a connector to a further line or to a terminal at a housing of a device or to a pneumatic or hydraulic installation are known in a large variety. The connections can be inputs or outputs. The lines can be composed of metal and/or of plastic and can be configured rigid or flexible. The screw elements can have the shape of hollow bolts or of screw sockets or can be configured as a sleeve nut. Also screw elements for the fastening of electric lines to electric devices are used. Such screw elements frequently have the shape of hollow screw bolts which comprise a ring-shaped sealing element and/or a clamping element for the line, as well as a line guided through the sealing element.
In particular in the field of the analytical, preparatory or industrial chromatography and in the field of medical diagnostics and in the field of laboratory devices in general, relatively thin hoses of plastic, which in operation are frequently subjected to a high pressure, are frequently connected to the corresponding devices by means of a screw elements of plastic, for example, to HPLC devices, MPLC devices or LPLC devices and/or to chromatography columns. In this connection a considerable number of lines can be connected to a device. It happens time and again that the accessibility of the screw elements is difficult due to the limited spatial conditions. In this connection, it can indeed happen that corresponding screw elements can only be turned over small angular ranges. Under these circumstances it is also difficult to ensure that the screw elements are sufficiently tightened, however, not so tight that the thread of the screw element, which is frequently composed of plastic, is damaged or that the screw element is tightened so hard that the seal of the plastic hose is no longer ensured be it due to a deformation or a damaging of the hose and/or of a provided seal.
Furthermore, a problem exists with respect to screw elements in that, due to the narrow spatial conditions it, is striven for to make the screw elements themselves as small as possible. Since the lines which are guided through the screw elements take on a considerable areal region of the end face of the screw element and cannot always be made smaller, the space available for the attachment of the fastening tool is very limited. The problem is in many cases even more pronounced when protectors against kinks for the flexible lines are provided, for example, having the shape of spiral wires, since space has to also be provided for these elements. Moreover, due to the narrow spatial conditions it is frequently difficult to place a fastening tool at the screw elements.